var W3CDOM = (document.getElementsByTagName && document.createElement);
var xhReq = createXMLHttpRequest();
var firstError;
var validForm;

SafeAddOnload(setupValidator)

function setupValidator () {
   document.forms[0].onsubmit = function () {
       return validateForm()
   }
}

function validateForm() {
   validForm = true;
   errorstring = '';
   var x = document.forms[0].elements;
   x['submit'].value = 'Validating...'
   x['submit'].disabled = true
   if (!x['uid'].value) {
       writeError(x['uid'],'An identifier must be set for a meeting.');
       validForm = false;
       if (!W3CDOM)
           alert(errorstring);
       if (firstError)
           firstError.focus();
       return validForm;
   } else {
       var URL ="/UMAS/ajax/check/meetingexists/?muid=" + x['uid'].value;
       xhReq.open("GET", URL, false);
       xhReq.send(null);
   }
   var serverResponse = xhReq.responseText;
   if ("true" == serverResponse) {  //then the meeting ID is already used.
       writeError(x['uid'],'The identifier ' + x['uid'].value + ' has already been used for another meeting. Please choose another.');
       validForm = false;
   }
   if (!x['title'].value) {
       writeError(x['title'],'Please enter a title for your meeting');
       validForm = false;
   }
   var startDate
   var endDate
   var now = new Date
   if (!x['startDate'].value) {
       writeError(x['startDate'],'Please enter a start date for the period you wish your meeting to take place in.');
       validForm = false;
   } else {
      startDate = getDate(x['startDate'].value)
   }
   if (!x['endDate'].value) {
       writeError(x['endDate'],'Please enter an end date for the period you wish your meeting to take place in.');
       validForm = false;
   } else {
      endDate = getDate(x['endDate'].value)
   }
   if (startDate && startDate < now) {
       writeError(x['startDate'],'The start date must be later than the current time.');
       validForm = false;
   }
   if (startDate && endDate && endDate < startDate) {
       writeError(x['endDate'],'The end date must be later than the start date.');
       validForm = false;
   }

   var splitDuration = x['duration'].value.split(" ")
   var days = parseInt(splitDuration[0])
   splitDuration = splitDuration[1].split(":")
   var hours = parseInt(splitDuration[0])
   var minutes = parseInt(splitDuration[1])

   if (days == 0 && hours == 0 && minutes == 0) {
       writeError(x['duration'],'The duration of a meeting must be at least 10 minutes.');
       validForm = false;
   }

   if (x['roomSize'].value && (!(IsNumeric(x['roomSize'].value)) || parseInt(x['roomSize'].value) < 1)) {
      writeError(x['roomSize'],'Please enter a positive number of participants in digits, or leave this field blank.');
      validForm = false;
   }

   if (!W3CDOM)
       alert(errorstring);
   if (firstError)
       firstError.focus();
   x['submit'].value = 'Create'
   x['submit'].disabled = false
   return validForm;
}


function writeError(obj,message) {
   if (obj.hasError) return;
   if (W3CDOM) {
       obj.className += ' error';
       obj.onchange = removeError;
       var sp = document.createElement('span');
       sp.className = 'error';
       sp.appendChild(document.createTextNode(message));
       obj.parentNode.appendChild(sp);
       obj.hasError = sp;
   } else {
       errorstring += obj.name + ': ' + message + '\n';
       obj.hasError = true;
   }
   if (validForm)
       firstError = obj;
   validForm = false;
}

function removeError() {
   this.className = this.className.substring(0,this.className.lastIndexOf(' '));
   this.parentNode.removeChild(this.hasError);
   this.hasError = null;
   this.onchange = null;
} 

// overloaded to allow setting via javascript to remove errors
function removeError2(obj) {
   if (obj.hasError) {
   obj.className = obj.className.substring(0,obj.className.lastIndexOf(' '));
   obj.parentNode.removeChild(obj.hasError);
   obj.hasError = null;
   obj.onchange = null;
   }
} 

function IsNumeric(sText)
{
   var ValidChars = "0123456789";
   var IsNumber=true;
   var Char;

   for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsNumber = false;
         }
      }
   return IsNumber;
}   

// ------------------------------------------------------------------
// getDate( date_string , format_string )
//
// This function takes a date string and a format string. It matches
// If the date string matches the format string, it returns the 
// getTime() of the date. If it does not match, it returns 0.
//
// This function taken from http://www.mattkruse.com/
// ------------------------------------------------------------------
function getDate(val) {
        format="yyyy/MM/dd HH:mm"
	val=val+"";
	format=format+"";
	var i_val=0;
	var i_format=0;
	var c="";
	var token="";
	var token2="";
	var x,y;
	var now=new Date();
	var year=now.getYear();
	var month=now.getMonth()+1;
	var date=1;
	var hh=now.getHours();
	var mm=now.getMinutes();
	var ss=now.getSeconds();
	var ampm="";
	
	while (i_format < format.length) {
		// Get next token from format string
		c=format.charAt(i_format);
		token="";
		while ((format.charAt(i_format)==c) && (i_format < format.length)) {
			token += format.charAt(i_format++);
			}
		// Extract contents of value based on format token
		if (token=="yyyy" || token=="yy" || token=="y") {
			if (token=="yyyy") { x=4;y=4; }
			if (token=="yy")   { x=2;y=2; }
			if (token=="y")    { x=2;y=4; }
			year=_getInt(val,i_val,x,y);
			if (year==null) { return 0; }
			i_val += year.length;
			if (year.length==2) {
				if (year > 70) { year=1900+(year-0); }
				else { year=2000+(year-0); }
				}
			}
		else if (token=="MMM"||token=="NNN"){
			month=0;
			for (var i=0; i<MONTH_NAMES.length; i++) {
				var month_name=MONTH_NAMES[i];
				if (val.substring(i_val,i_val+month_name.length).toLowerCase()==month_name.toLowerCase()) {
					if (token=="MMM"||(token=="NNN"&&i>11)) {
						month=i+1;
						if (month>12) { month -= 12; }
						i_val += month_name.length;
						break;
						}
					}
				}
			if ((month < 1)||(month>12)){return 0;}
			}
		else if (token=="EE"||token=="E"){
			for (var i=0; i<DAY_NAMES.length; i++) {
				var day_name=DAY_NAMES[i];
				if (val.substring(i_val,i_val+day_name.length).toLowerCase()==day_name.toLowerCase()) {
					i_val += day_name.length;
					break;
					}
				}
			}
		else if (token=="MM"||token=="M") {
			month=_getInt(val,i_val,token.length,2);
			if(month==null||(month<1)||(month>12)){return 0;}
			i_val+=month.length;}
		else if (token=="dd"||token=="d") {
			date=_getInt(val,i_val,token.length,2);
			if(date==null||(date<1)||(date>31)){return 0;}
			i_val+=date.length;}
		else if (token=="hh"||token=="h") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>12)){return 0;}
			i_val+=hh.length;}
		else if (token=="HH"||token=="H") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>23)){return 0;}
			i_val+=hh.length;}
		else if (token=="KK"||token=="K") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>11)){return 0;}
			i_val+=hh.length;}
		else if (token=="kk"||token=="k") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>24)){return 0;}
			i_val+=hh.length;hh--;}
		else if (token=="mm"||token=="m") {
			mm=_getInt(val,i_val,token.length,2);
			if(mm==null||(mm<0)||(mm>59)){return 0;}
			i_val+=mm.length;}
		else if (token=="ss"||token=="s") {
			ss=_getInt(val,i_val,token.length,2);
			if(ss==null||(ss<0)||(ss>59)){return 0;}
			i_val+=ss.length;}
		else if (token=="a") {
			if (val.substring(i_val,i_val+2).toLowerCase()=="am") {ampm="AM";}
			else if (val.substring(i_val,i_val+2).toLowerCase()=="pm") {ampm="PM";}
			else {return 0;}
			i_val+=2;}
		else {
			if (val.substring(i_val,i_val+token.length)!=token) {return 0;}
			else {i_val+=token.length;}
			}
		}
	// If there are any trailing characters left in the value, it doesn't match
	if (i_val != val.length) { return 0; }
	// Is date valid for month?
	if (month==2) {
		// Check for leap year
		if ( ( (year%4==0)&&(year%100 != 0) ) || (year%400==0) ) { // leap year
			if (date > 29){ return 0; }
			}
		else { if (date > 28) { return 0; } }
		}
	if ((month==4)||(month==6)||(month==9)||(month==11)) {
		if (date > 30) { return 0; }
		}
	// Correct hours value
	if (hh<12 && ampm=="PM") { hh=hh-0+12; }
	else if (hh>11 && ampm=="AM") { hh-=12; }
	var newdate=new Date(year,month-1,date,hh,mm,ss);
	return newdate.getTime();
	}
// ------------------------------------------------------------------
// Utility functions for parsing in getDateFromFormat()
// ------------------------------------------------------------------
function _isInteger(val) {
	var digits="1234567890";
	for (var i=0; i < val.length; i++) {
		if (digits.indexOf(val.charAt(i))==-1) { return false; }
		}
	return true;
	}
function _getInt(str,i,minlength,maxlength) {
	for (var x=maxlength; x>=minlength; x--) {
		var token=str.substring(i,i+x);
		if (token.length < minlength) { return null; }
		if (_isInteger(token)) { return token; }
		}
	return null;
	}